From WordNet (r) 2.0 (August 2003) [wn]:
minefield
n : a region in which explosives mines have been placed
From The Collaborative International Dictionary of English v.0.48 [gcide]:
minefield \minefield\ n.
1. (Mil.) a region in which explosive mines[4] have been
placed, especially a region on land.
[WordNet 1.5]
2. Hence: (Fig.) A situation in which a simple mistake can
have disastrous consequences; a touchy or dangerous
situation requiring great caution; as, the candidate
threaded his way skillfully through a minefield of loaded
questions from the audience.
[PJC]